1. Field of the Invention
The present invention relates to a photo conductor that has a protective surface layer, the photo conductor being utilized in image forming apparatus that uses the photo conductor, and a method for producing photo conductor that has the protective surface layer.
2. Description of Related Art
Conventionally, the characteristics of photo conductor (in particular, sensitivity and residual potential) with excellent durability and which sufficiently satisfy functions as a photo conductor have existed as organic photo conductor that has a protective surface layer. This is an organic photo conductor provided with a plasma polymerized membrane on a protective surface layer.
For example, a technique is known to form on and over a resin layer a composition of a protective surface layer of an organic photo conductor that has an organic light conductive layer into a two layer composition of a very protective surface layer having an amorphous hydrocarbon membrane (a -C membrane: amorphous carbon) created by a plasma polymerization method to achieve a product with photo conductor properties that is especially sensitive without losing any residual potential and also has excellent durability (for example, Related Art 1).
[Related Art 1] Japanese Patent Publication No. 2,590,971
A conventional organic photo conductor provided with a protective surface layer having amorphous carbon has problems such as poor adhesion between the carrier transport layer that has the protective surface layer and organic resin, the protective surface layer being scraped due to scratches which occur when printing if the number of prints increases thereby reducing the lifespan of the organic photo conductor itself.
Furthermore, an organic photo conductor provided with a protective surface layer having amorphous carbon also has a problem of the decreased electrical resistance of a protective surface layer having deposition layers of amorphous carbon created by plasma CVD (chemical vapor deposition) of hydrocarbon gas diluted by argon gas or hydrocarbon gas only. Therefore, the image resolution becomes worsened.
Even further, an organic photo conductor provided with a protective surface layer having amorphous carbon also has a problem in which if the number of prints increases, the surface electrical resistance of foreign material adhering to the protective surface layer will decrease thereby worsening the image resolution after the image forming apparatus has not been used for a long period of time or during operation in high temperature/high humidity.